Add the check for the return value of kzalloc in order to avoid
NULL pointer dereference.
Moreover, use the goto-label to share the clean code.

Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
Changelog:

v3 -> v4:

1. Move the check right after the kzalloc.

v2 -> v3:

1. Use "while (i--)" to simplify the code.

v1 -> v2:

1. Use goto-label to share the clean code.
---
 drivers/net/ethernet/intel/ice/ice_gnss.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c
index b5a7f246d230..60b6c7125616 100644
--- a/drivers/net/ethernet/intel/ice/ice_gnss.c
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.c
@@ -460,6 +460,9 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf)
 	for (i = 0; i < ICE_GNSS_TTY_MINOR_DEVICES; i++) {
 		pf->gnss_tty_port[i] = kzalloc(sizeof(*pf->gnss_tty_port[i]),
 					       GFP_KERNEL);
+		if (!pf->gnss_tty_port[i])
+			goto err_out;
+
 		pf->gnss_serial[i] = NULL;
 
 		tty_port_init(pf->gnss_tty_port[i]);
@@ -469,21 +472,23 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf)
 	err = tty_register_driver(tty_driver);
 	if (err) {
 		dev_err(dev, "Failed to register TTY driver err=%d\n", err);
-
-		for (i = 0; i < ICE_GNSS_TTY_MINOR_DEVICES; i++) {
-			tty_port_destroy(pf->gnss_tty_port[i]);
-			kfree(pf->gnss_tty_port[i]);
-		}
-		kfree(ttydrv_name);
-		tty_driver_kref_put(pf->ice_gnss_tty_driver);
-
-		return NULL;
+		goto err_out;
 	}
 
 	for (i = 0; i < ICE_GNSS_TTY_MINOR_DEVICES; i++)
 		dev_info(dev, "%s%d registered\n", ttydrv_name, i);
 
 	return tty_driver;
+
+err_out:
+	while (i--) {
+		tty_port_destroy(pf->gnss_tty_port[i]);
+		kfree(pf->gnss_tty_port[i]);
+	}
+	kfree(ttydrv_name);
+	tty_driver_kref_put(pf->ice_gnss_tty_driver);
+
+	return NULL;
 }
 
 /**
-- 
2.25.1

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Jiasheng Jiang
> Sent: Thursday, December 8, 2022 7:06 PM
> To: jiri@resnulli.us
> Cc: leon@kernel.org; intel-wired-lan@lists.osuosl.org; Jiasheng Jiang
> <jiasheng@iscas.ac.cn>; Brandeburg, Jesse <jesse.brandeburg@intel.com>;
> linux-kernel@vger.kernel.org; edumazet@google.com; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; netdev@vger.kernel.org; kuba@kernel.org;
> pabeni@redhat.com; davem@davemloft.net
> Subject: [Intel-wired-lan] [PATCH net v4] ice: Add check for kzalloc
> 
> Add the check for the return value of kzalloc in order to avoid NULL pointer
> dereference.
> Moreover, use the goto-label to share the clean code.
> 
> Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
> Changelog:
> 
> v3 -> v4:
> 
> 1. Move the check right after the kzalloc.
> 
> v2 -> v3:
> 
> 1. Use "while (i--)" to simplify the code.
> 
> v1 -> v2:
> 
> 1. Use goto-label to share the clean code.
> ---
>  drivers/net/ethernet/intel/ice/ice_gnss.c | 23 ++++++++++++++---------
>  1 file changed, 14 insertions(+), 9 deletions(-)
> 

Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)

Thu, Dec 08, 2022 at 02:35:52PM CET, jiasheng@iscas.ac.cn wrote:
>Add the check for the return value of kzalloc in order to avoid
>NULL pointer dereference.
>Moreover, use the goto-label to share the clean code.
>
>Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY")
>Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>